1. Field of the Invention
The present invention relates to a system-on-chip having an n×n mesh topology structure. More particularly, the present invention relates to establishing paths between routers of a system-on-chip.
2. Description of Related Art
To facilitate Internet access or computing functions of digital data equipment like cell phones, PDAs (Personal Digital Assistants), digital TVs, and smart phones, a number of semiconductor chips including microprocessor, network chip, and memory are required. As the data equipment has become more complicated, integration among these products is already occurring and will become a necessity in near future. If that happens, even more chips will be required within one single data device.
Developed as an answer to the above is a System-on-a-Chip (SoC) technology which integrates features of every component (even semiconductors) on a single chip. In general, the SoC system is constructed of a computing element, input and output (I/O), logic, and memory. The compact and high-integration SoC features high performance and low power consumption, so a majority of data equipment will benefit from the SoC technology. Intellectual property (IP) is also used to help designers to create the semiconductor chip much more rapidly. The IP is a design block that is specially developed as a ready-to-use application to the single chip.
A number of technologies have been devised to realize the SoC, and approaches connecting various IPs embedded in a chip have been addressed as a critical factor. There are two approaches connecting the various IPs, one using a bus structure and the other using a network structure. However, the bus architecture already reached its structural limit as the amount of data transmitted/received between IPs increases. This is because when a specific IP uses a bus, and other IPs cannot use the bus at all. That is, the specific IP exclusively uses the bus.
Moreover, the bus architecture is not extendable but fixed, so that additional IPs of the chip cannot be connected to a bus. As an attempt to solve the performance drawback of the bus architecture, network architecture has been devised to connect IPs. Furthermore, the network structure has an advantage of low power consumption compared to the bus structure. Hereinafter, the network structure is referred to as networks-on-chip (NoC). The NoC architecture causes a problem when general network technologies are applied since networks are designed on the IPs embedded in a chip.
According to another aspect of the present invention, there is provided a method of establishing a path between routers in a system-on-chip of n×n mesh topology structure, including: originating, via a router, a routing packet; setting a hop counter of the routing packet to 1; broadcasting the routing packet from the router to at least one neighboring router; generating a token packet having a destination address indicating an address of an IP connected to first router; and broadcasting the token packet to the at least one neighboring router.
According to another aspect of the present invention, there is provided a method of establishing a path between routers in a system-on-chip of n×n mesh topology structure, including: comparing, when a routing packet is received from a neighboring router, a hop counter of the routing packet to 2(n−1), reading a source address from the received routing packet when the hop counter of the received routing packet is determined to be less than 2(n−1), and discarding the received routing packet when the hop counter of the received routing packet is determined not to be less than 2(n−1), 2(n−1) being a smallest hop number to a router positioned at n×n from a router positioned at 1×1 and of the n×n mesh topology; determining whether the read address is a new address, updating a routing table using the received routing packet when the read address is a new address, and comparing the hop counter of the received routing packet to a stored hop counter for the source address stored in the routing table when the read address is not a new address; updating the routing table when the hop counter of the received routing packet is determined in the comparing the hop counter of the received routing packet to a stored hop counter to be less than or equal to the hop counter stored in the routing table; updating the hop counter of the received routing packet when the hop counter of the received routing packet is determined in the comparing the hop counter of the received routing packet to a stored hop counter to be larger than the hop counter stored in the routing table; and determining whether a destination address of a received token packet is the same as that of the router; sending the routing packet data to an IP connected thereto when the destination address is determined to be the same, and broadcasting the updated received router packet to at least another neighboring router when the destination address is determined not to be the same.
According to another aspect of the present invention, there is provided a method of establishing a path between routers in a system-on-chip of n×n mesh topology structure, including: reading a destination address of a received token packet received by a receiving router from a neighboring router; comparing the read destination address to the address of the receiving router; generating a routing packet including information about the receiving router when the addresses are determined to be the same, and discarding the received token packet when the addresses are determined not to be the same; broadcasting the generated routing packet to at least one neighboring router; designating a router to generate a next routing packet; generating a token packet having a destination address of the designated router; and broadcasting the generated token packet to the at least one neighboring router.
According to another aspect of the present invention, there is provided a method of establishing multiple paths for data transmission, including: receiving data and a destination address of the data from a neighboring router; determining whether x-direction position information of the received destination address is the same as x-direction position information of a receiving router; sending the received data to a router based on the determining of x-direction information; determining whether the y-direction position information of the received destination address is the same as y-direction position information of the receiving router; and sending the received data a router based on the determining of y-direction information.